Induction motor control system with voltage controlled oscillator circuit

A voltage controlled oscillator circuit is reported in which there are employed first and second differential amplifiers. The first differential amplifier, being employed as an integrator, develops equal and opposite slopes proportional to an input voltage, and the second differential amplifier functions as a comparator to detect equal amplitude positive and negative selected limits and provides switching signals which gate a transistor switch. The integrating differential amplifier is switched between charging and discharging modes to provide an output of the first differential amplifier which upon the application of wave shaping provides a substantially sinusoidal output signal. A two phased version with a second integrator provides a second 90 deg phase shifted output for induction motor control

Draft of an Obituary (Written by the Deceased, Three Days Before Her Death)

pages 101-11

Contour measurement system

A measurement system for measuring the departures from a straight line of discrete track sections of a track along a coal face in a mine employing a vehicle having a pair of spaced wheel assemblies which align with the track is presented. A reference arm pivotally connects between the wheel assemblies, and there is indicating means for measuring the angle of pivot between the arm and each of the wheel assemblies. The length of the device is less than the length of a track section, and thus when one of the wheel assemblies is on one track section and one is on an adjoining track section, the sum of the indicated angles will be indicative of the angle between track sections. Thus, from the length of a track section and angle, the departure of each track section from the line may be calculated

An archival case study : revisiting the life and political economy of Lauchlin Currie

This paper forms part of a wider project to show the significance of archival material on distinguished economists, in this case Lauchlin Currie (1902-93), who studied and taught at Harvard before entering government service at the US Treasury and Federal Reserve Board as the intellectual leader of Roosevelt's New Deal, 1934-39, as FDR's White House economic adviser in peace and war, 1939-45, and as a post-war development economist. It discusses the uses made of the written and oral material available when the author was writing his intellectual biography of Currie (Duke University Press 1990) while Currie was still alive, and the significance of the material that has come to light after Currie's death

The Inhibitory Effects of Carbonaceous Materials on the Cyaniding of Gold Ores.

Carbon and carbonaceous material have been known to have a deleterious effect upon the cyanidation of gold and silver ores since the very beginning of the process. Organic matter is a common source of impu­rities in cyanide solution, its reducing effect being notorious

The pursuit of isotopic and molecular fire tracers in the polar atmosphere and cryosphere

We present an overview of recent multidisciplinary, multi-institutional efforts to identify and date major sources of combustion aerosol in the current and paleoatmospheres. The work was stimulated, in part, by an atmospheric particle \u27sample of opportunity\u27 collected at Summit, Greenland in August 1994, that bore the 14C imprint of biomass burning. During the summer field seasons of 1995 and 1996, we collected air filter, surface snow and snowpit samples to investigate chemical and isotopic evidence of combustion particles that had been transported from distant fires. Among the chemical tracers employed for source identification are organic acids, potassium and ammonium ions, and elemental and organic components of carbonaceous particles. Ion chromatography, performed by members of the Climate Change Research Center (University of New Hampshire), has been especially valuable in indicating periods at Summit that were likely to have been affected by the long range transport of biomass burning aerosol. Univariate and multivariate patterns of the ion concentrations in the snow and ice pinpointed surface and snowpit samples for the direct analysis of particulate (soot) carbon and carbon isotopes. The research at NIST is focusing on graphitic and polycyclic aromatic carbon, which serve as almost certain indicators of fire, and measurements of carbon isotopes, especially 14C, to distinguish fossil and biomass combustion sources. Complementing the chemical and isotopic record, are direct \u27visual\u27 (satellite imagery) records and less direct backtrajectory records, to indicate geographic source regions and transport paths. In this paper we illustrate the unique way in which the synthesis of the chemical, isotopic, satellite and trajectory data enhances our ability to develop the recent history of the formation and transport of soot deposited in the polar snow and ice

Hubble Space Telescope Planetary Camera Images of NGC 1316

We present HST Planetary Camera V and I~band images of the central region of the peculiar giant elliptical galaxy NGC 1316. The inner profile is well fit by a nonisothermal core model with a core radius of 0.41" +/- 0.02" (34 pc). At an assumed distance of 16.9 Mpc, the deprojected luminosity density reaches \sim 2.0 \times 10^3 L_{\sun} pc$^{-3}$. Outside the inner two or three arcseconds, a constant mass-to-light ratio of $\sim 2.2 \pm 0.2$ is found to fit the observed line width measurements. The line width measurements of the center indicate the existence of either a central dark object of mass 2 \times 10^9 M_{\sun}, an increase in the stellar mass-to-light ratio by at least a factor of two for the inner few arcseconds, or perhaps increasing radial orbit anisotropy towards the center. The mass-to-light ratio run in the center of NGC 1316 resembles that of many other giant ellipticals, some of which are known from other evidence to harbor central massive dark objects (MDO's). We also examine twenty globular clusters associated with NGC 1316 and report their brightnesses, colors, and limits on tidal radii. The brightest cluster has a luminosity of 9.9 \times 10^6 L_{\sun} ($M_V = -12.7$), and the faintest detectable cluster has a luminosity of 2.4 \times 10^5 L_{\sun} ($M_V = -8.6$). The globular clusters are just barely resolved, but their core radii are too small to be measured. The tidal radii in this region appear to be $\le$ 35 pc. Although this galaxy seems to have undergone a substantial merger in the recent past, young globular clusters are not detected.Comment: 21 pages, latex, postscript figures available at ftp://delphi.umd.edu/pub/outgoing/eshaya/fornax

Recent Cases

Constitutional Law-First Amendment-School Authorities May Prohibit High School Student\u27s Distribution of Sex Questionnaire to Prevent Possible Psychological Harm to Other Students Robert Edward Banta Plaintiff, editor of a high school publication,\u27 brought suit in federal court seeking an order compelling defendant school officials to allow the student publication to distribute a sex questionnaire,to students in the high school and to publish the results. Plaintiff claimed that defendants had not shown that the planned distribution would disrupt school activities and that, therefore, defendants\u27prohibition of the questionnaire violated 42 U.S.C. § 19831 and the first and fourteenth amendments. Pointing to potential psychological harm to students, defendants argued that the state\u27s interest in protecting the students\u27 emotional well-being outweighed plaintiffs interest in distributing the questionnaire. The trial court held that defendants could prohibit distribution of the questionnaire to ninth-and tenth-grade students but not to eleventh- and twelfth-grade students. On appeal to the United States Court of Appeals for the Second Circuit, held, reversed in part\u27 and remanded with instructions to dismiss the complaint. If school officials reasonably believe that distribution on school grounds of a high school student\u27s questionnaire soliciting information about the sexual habits of his fellow students might cause psychological harm to other students, then prohibition of the questionnaire does not violate the right to freedom of expression of the student seeking to distribute the questionnaire. Trachtman v. Anker, 563 F.2d 512 (2d Cir. 1977). Corporations--Freeze-Out Mergers--The Delaware Supreme Court Requires Majority Shareholder Proof of a Valid Business Purpose As a Component of Entire Fairness in Freeze-Out Merger Challenges Oby T. Brewer, III Recent declines in stock market averages\u27 accompanied by costly disclosure requirements imposed under the federal securities laws have prompted many companies to reconsider their positions as publicly held corporations. In response to the resulting minimal benefits of public ownership, many controlling shareholders now seek to increase their control and participation in a corporation\u27s future profits by going private.\u27 One means of going private is the freeze-out merger, by which a parent company forces the liquidation of minority interests in a publicly held subsidiary through a merger of the subsidiary with the parent. By complying with applicable state merger statutes, the parent may eliminate the minority\u27s shares by tendering a cash-out price, which the minority either must accept or have appraised judicially. The merger statutes thus represent a legislative compromise between total majority control and the single vote veto available to the minority at common law. Criminal Procedure--Prosecutorial Immunity-Federal Prosecutor Is Not Absolutely Immune From Suit for Alleged Perjury Cornelia Anne Clark Plaintiffs\u27 brought a civil action in tort charging that defendant federal prosecutor\u27s alleged perjury at a hearing incident to a grand jury investigation of plaintiffs\u27 activities\u27 violated their constitutional rights. On motion to dismiss, defendant contended that he enjoyed absolute quasi-judicial immunity because he had been acting at the hearing in his official capacity as a special federal prosecutor. The district court\u27 denied the motion, holding that the doctrine of quasi-judicial immunity does not apply when the prosecutor is alleged to have committed perjury. On interlocutory appeal to the United States Court of Appeals for the District of Columbia Circuit, held, affirmed. Because a federal prosecutor\u27s perjury during a court hearing incident and prior to a grand jury investigation falls within his investigative duty rather than his advocatory duty,the prosecutor is entitled only to a qualified immunity.\u27 Briggs v.Goodwin, No. 75-1642 (D.C. Cir. Sept. 21, 1977). Securities Law--Rule 10b-5-Defense of In Pari Delicto Bars Private Damage Action Brought Against Tipper by Tippee Who Fails to Disclose Before Trading Terry Currie Tippees\u27 brought a private action for damages under section 10(b) of the Securities Exchange Act of 1934 and rule 10b-53 charging that defendant tippers disseminated false and misleading material inside information in advising plaintiffs of an imminent merger between two corporations that would result in appreciated stock values.\u27 In reliance on this information, plaintiffs purchased stock in one of the corporations and subsequently incurred substantial losses on the stock when the proposed merger did not occur. Defendants moved for summary judgment, claiming that the doctrine of in pari delicto barred plaintiffs\u27 recovery because plaintiffs also had violated rule 10b-5 by failing to make full disclosure of the inside information before trading on the open market.\u27 The district court granted the tippers\u27 motion for summary judgment. On appeal to the United States Court of Appeals for the Third Circuit, held, affirmed. When a tippee violates rule 10b-5 by failing to make full disclosure to the investing public of material inside information prior to trading on the open market, the defense of in pari delicto bars a rule 10b-5 private damage action by the tippee against the tipper. Torts--Negligence--Child Has Cause of Action for Preconception Medical Malpractice Douglas William Ey, Jr. Plaintiff, claiming that she suffered permanent physical injuries\u27 as a result of defendants\u27 conduct prior to her conception,sought to recover damages in a negligence action.2 In 1965 plaintiffs mother,who had Rh negative blood, was given two transfusions of incompatible Rh positive blood in defendant hospital where defendant physician was director of laboratories.\u27 Plaintiff\u27s mother did not discover that these transfusions had sensitized her blood until shortly before plaintiffs birth in 1973. Defendants moved to dis-miss for failure to state a cause of action, arguing that because plaintiff had not been conceived at the time of the alleged negligent conduct, defendants owed no duty of care to plaintiff. The trial court granted defendants\u27 motion, but the Illinois Appellate Court reversed and remanded the case for further proceedings. On appeal to the Supreme Court of Illinois, held, affirmed. A child injured by the negligent acts of a physician and a hospital committed against his mother prior to his conception has a cause of action based on negligence. Renslow v. Mennonite Hospital, 367 N.E.2d 1250 (Ill.1977)